Warp stop mechanism for looms



H. H. BURTON WARP STOP MECHANISM FOR LOOMS April M 2 6 1927.

Filed July 21. 1926 l E (i/k vmaz I; I I I ATTORNEY Patented Apr. 26, 192-7.

UNITED STATES ATENT, OFFICE.

HARRY H. BURTON, OF NEW BEDFORD, MASSACHUSETTS, ASSIGNOR T DRAP ER COR- PORATION, OF HOPEDALE, MASSACHUSETTS, A CORPORATION OF MAINE.

WARP s'ror MECHANISM non Looms.

Application filed July 21,

of warp stop mechanisms to provide dropwires having elongated slots through which the detector bar and detector bar holder extend and by which the drop Wires are guided in their movements when released by a warp thread. When the drop wire is released by a too slack or broken warp thread, it should at en age between the teeth of the detector bar ho der and the similar teeth of .the' detector bar, whereby the latter is arrested in its transverse movement and loom stoppage is effected.

Where the drop wires are formed of sheet material, such as light sheet metal, the elongated slot is usually out in the drop wire and is formed of substantially the same 7 width throughout, and the top portion or wall of the slot is usually formed on'a curve 'or rounded; In such character of warp stop motion, a drop wire may not fall sufiiciently far to engage the teeth of the detector bar, but the side portions ofthe elongated slot where it rounds into the upper wall of the slot are liable at times to blnd against the detector bar holder, of which there are usually two'members, one at each side of the detector bar. Should this happemas it does at times, the loom will continue in operation, thus weaving imperfect cloth, due to the failure of the drop wire to pass completely into locking relation with the detector bar and detector bar holder.

It may happen at times, also, that lint will accumulate on the top of the teeth of the detector bar holder, so that if a drop wire falls it may not only bind against the side walls of the detector car holder, but the-lint itself will at times prevent the top wall of the slot from passing into engagement with the teeth of the detector bar and the loom will continue in operation. I

The -ob ect of the present invention is to provide a mechanical warp st p mechanism 1926. Serial No. 123,959.

wherein the detector bar has a movement transversely of the 100m and is associated with a detector bar holder having similar sheet metal and the elongated .slot which embraces the detector bar and detector bar holder is cut out by a die, and similarly the widened portion of the elongated slot at its upper end is cut out to provide diverging side Walls connected by a straight upper wall at the upper end of the widened slot thus formed.

In the drawings:

Fig. 1 is a perspective view of a portion of a warp stop mechanism the present invention;

Fig. 2 is anenlarge'd cross-sectional view showing a drop wire normally held in raised position during weaving;

Fig. 3 is a view similar to that of Fig. 2 showing the drop. wire as having been released by a broken'warp thread and the top wall of the enlarged upper opening resting upon the upper surface of the teeth formed in the detector bar holder; and

Fig. 4 is a view similar to that of Figs. 2 and 3 but showlng the drop wire as'having fallen completely into locking engagementwith the teeth of the detector bar and detector bar holder, the upper position of the .drop wire being indicated by dotted lines.

provided with The warp stop mechanism with which the I present invention is'associated is of the type wherein the detector barhas teeth and is given a detecting movement transversely of the loom, while the detector bar holder is a fixed element having similar teeth, and associated with the detector bar and detector bar holder is a series of drop wires which are normally supported by the warp thread durin weaving but which, when a warp threa breaks or becomes too slack, drop into engagement with the detector bar and detector bar holder and arrest movement of the detector'bar; The means for arresting theloom operation on the occurrence of a. warp fault is not herein shown because it forms no essential part of the present invention, which is more particularly concerned with the particular character of the drop wire. i

In the drawings a support 1 (usually one at each side of the loom) serves as a means of sustaining the operating parts of the stop motion. The sup ort 1, only one of which is shown, is provi ed with an opening into which extends the detector bar holder 2.

In the present instance of the invention, the detector bar holder 2 is formed in duplicate, and these are separated at their lower portions by a spacer 3, .and in the spaces between the detector bar holder members 2 is the detector bar 4. The detector bar holder 2 (whether there be one or more) may be suitably secured to the supports 1 by means of a bolt 5 which may pass through a slot 6 formedin the laterally extending portion 7 of the detector bar 4. The lateral extension 7 of the detector bar may be utilized as a means of associating the detector bar with to the teeth in the detector bar holder, but

the upwardly extending teeth of the detector bar project slightly above the top surface of the teeth of the detector bar holder, the result being that should a drop wire (as will later appear) be released by a broken or too slack warp thread, it may dro upon the top surface of the' teeth of the etector bar holder and on the reciprocating move ment of the detector bar-it will be moved detector bar holder and thereby efi'ect stoppage of the detector bar and the arrest of loom operation. l

The drop wires 11, of which only one is shown in the present illustration of the invention, may be of the usual hair pin type in which the downwardly extending legs 12 have a space 13 between them, 'throu h which may be passed a warp thread a for t e normal support of the drop wire during weaving, as. indicated in Fig. 1.

'The upper portion of the dropwire 11 is provided with an elongated slot 14, the side walls 15 of which are s aced apart a suflicient distance to include etween them the detector bar'and detector bar holder,

with the result that the parallel side walls 15 of the elongated slot act as guides in con unction with the detector bar holder. to .dlrect the movement of the drop wire.

The upper portion of the elongated slot 14 in the drop wire is of novel construction to insure engagement of the drop wire with the detector ,bar and detector bar holder teeth when a' drop wire fails to be supported by a warp thread.

Asindicated. the upper portion of the elongated slot 14 is widened, a condition which may best be effected by cutting the metal of the drop wire divergently from the'upper end portion l6 of the elongated slot at each side thereof, thereby producing at the upper extremity of the elongated slot the outwardly or divergent side walls17 in the drop wire, the upper edge of said side walls being joined by a straight wall 18.

Should a drop wire be released by a too slack or broken warp thread, the divergent side walls 17 and the straight wall connecting the upper portions of the divergent side walls, insure that the drop wire shall pass fully into engagement with the teeth of the detector bar and detector bar holder. Should a drop wire 11, as indicated in Fi 3, be released by a broken warp thread, w ile the top wall 18 of the widened slot is directly above the teeth 8 in the detector bar holder, the straight wall 18 will insure that it will rest. upon the top surfaces of the teeth of the detector bar holder, so that when a. tooth 10 of the detector bar meets the side of the straight wall 18, thedrop wire will be pushed along the detector bar holder until it passes into the space between the teeth thereof, whereupon loom stoppage is effected.

Should a drop wire be released by a broken warp thread when it is above the space'between the teeth of the detector bar holder, it will fall directly between the teeth of the detector bar holder, as indicated in Fig. 4, and upon engagement by the teeth of the detector bar will arrest movement of the latter and efi'ect loom stoppage. 1nto engagement between the teeth of the i In warp stop mechanisms of this general type, it sometimeshappens that lint will accumulate on the top of the teeth of the detector bar holder which is stationary, and in such case the space formed by the diverging side walls 17 of the widened portion of the slot. provides a pocket into which the lint may readily pass when the drop wire is released by a broken warp thread.

The construction of the drop wire, as hereinbefore described, afiords a sure and rehable means in a warp stop mechanism of the type indicated for effecting loom stop-' page whenever a warp thread-breaks or becomes too slack, and this is secured by the straight wall 18 at the upper terminal portion of the widened slot' and the dive nt side walls forming the widened slot a ve the elon ted detector fslot.

What is claimed is:" In a mechanical .warp stop motion for looms, the combination of a detector bar and detector bar holder each having rectangular teeth with straight upper supporting surfaces and rectangular spaces between, a

series of drop wires each provided .with an elongated detector slothaving parallel side walls between which the detector. bar and detector bar holder extend, and a top opening communicating with the detector slot and having upwardly diverging side walls, a straight top wall connecting the upper portion of the diverging side Walls of said top opening and of a straight length greater than the combined thickness of the detector bar and detector liar holder that the straight top wall of the opening may engage and be sup iorted hy the straight upper supporting surfaces of the rectangular teeth of either the detector ha r or detector har holder upon t-he ocemrence of a warp fault, and an opening inde wndent ol' the top opening in drop wires for sustaining the drop wires upon the warp threads.

'In testimony whereof, I have signed my name to this specification.

HARRY H; BURTON. 

